Aerial shoots 10-70 cm, from caudices, caudices ascending to vertical. Basal leaves 3-6(-10), 1-2-ternate; petiole (2-)4-10(-14) cm; terminal leaflet petiolulate to ±sessile, broadly and irregularly rhombic to obovate, (1.5-)2.5-4.5(-5.5) × (1-)3-10 cm, base narrowly cuneate, margins incised on distal 1/3, apex broadly acute to nearly obtuse; surfaces abaxially villous-silky, hispid to villous, or sparsely long-pilose, adaxially glabrous, nearly glabrous, villous-silky, or hispid to villous; lateral leaflets (2-)3×-parted; ultimate segments (1.5-)2-3.5(-5) mm wide. Inflorescences 2-7-flowered cymes or flowers solitary; peduncle villous, pilose, or hispid to villous; involucral bracts usually 3-5, occasionally 2 in secondary involucres, 1-2-tiered, ternate, occasionally incompletely ternate, ±similar to basal leaves, greatly reduced, bases distinct; terminal leaflet petiolulate to ±sessile, broadly and irregularly rhombic to obovate, (1.5-)3-4(-5) × 0.5-1(-2) cm, base narrowly cuneate, margins incised on distal 1/3, apex broadly acute to nearly obtuse, surfaces abaxially hispid to villous, villous-silky, or sparsely long-pilose, adaxially glabrous, nearly glabrous, hispid to villous, or villous-silky; lateral leaflets (2-)3×-parted or -lobed, lobes frequently unequal; ultimate lobes 1.5-3(-4.3) mm wide. Flowers: sepals 5-9, green to yellow, blue, purple, red, or occasionally white, or abaxially blue, red, yellow and red, or purple, or tinged purple, adaxially white, yellow, yellow and red, blue, or tinged purple, ovate to oblong, 5-17 × (3.5-)5-7(-9) mm, abaxially hairy, adaxially glabrous; stamens 50-80. Heads of achenes spheric; pedicel 6-15(-23) cm. Achenes: body irregularly ellipsoid or elliptic, flat, 3-4 × 1.5-2 mm, not winged, tomentose, woolly, or villous; beak ±straight, distally recurved or strongly hooked, 1-6 mm, glabrous.
G.Boraiah and M.Heimburger (1964) conducted an extensive cytotaxonomic analysis of this wide-ranging and extremely variable species and its relatives. The present treatment takes a broader view of the species (and its variation) and recognizes fewer entities. In addition, Anemone tetonensis and A . stylosa , plants treated as closely related species by G.Boraiah and M.Heimburger, are treated here as varieties of A . multifida .
Early-season plants of Anemone multifida var. multifida have solitary flowers and will key to var. saxicola . Anemone multifida var. tetonensis and especially var. saxicola might be based on characteristics that are influenced primarily by environment; further study is warranted.
Native Americans used Anemone multifida (no varieties specified) medicinally as an antirheumatic, cold remedy, nosebleed cure, and general panacea, as well as a means of killing lice and fleas (D. E. Moerman 1986).
Plants 1-6 dm, from a stout, often branched caudex, usually villous; basal lvs long-petioled, deeply 3-parted, the segments deeply incised or lobed into acute, linear- oblong divisions; involucral lvs similar but subsessile; peduncles 1-3, the lateral ones often with a small secondary involucre; sep 5-9, white, yellowish, or red, 5-15 mm; fruiting head subglobose; achenes 2-3.5 mm, densely woolly; style short, glabrous; 2n=32. Shores and rocky banks in calcareous soil; Nf. to Alas., s. to Me., Vt., n. N.Y., n. Mich., S.D., N.M., and Calif.; s. S. Amer. May, June. Our plants, sometimes distinguished as var. hudsoniana DC., are scarcely separable from the South American var. multifida sens. strict.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.